var wall = new Array();

// Header Image 
wall[0] = "img/header/header0.jpg";
wall[1] = "img/header/header1.jpg";
wall[2] = "img/header/header2.jpg";
wall[3] = "img/header/header3.jpg";
wall[4] = "img/header/header4.jpg";
wall[5] = "img/header/header5.jpg";

var rnd = Math.floor((Math.random() * 100)) % wall.length;
document.write('<style type="text/css">#header { background-image:url(' , wall[rnd] , '); }</style>');